Radio frequency identification system

ABSTRACT

A radio frequency identification system, and method of operation thereof, provides: a sensor for sensing the absence or presence of a radio frequency identification transponder at the radio frequency identification system; a supply system connected to the sensor for supplying the radio frequency identification transponder to the radio frequency identification system in the absence of the radio frequency identification transponder at the radio frequency identification system; and a programmer connected to the sensor for writing transponder content to the radio frequency identification transponder at the radio frequency identification system in the presence of the radio frequency identification transponder at the radio frequency identification system.

This application is a continuation of U.S. application Ser. No.14/746,343 filed Jun. 22, 2015, which is a continuation of U.S.application No. 13/440,635 filed Apr. 5, 2012, which is a continuationof U.S. application Ser. No. 12/067,046, filed Mar. 15, 2008, and issuedas U.S. Pat. No. 8,179,259, which claims the benefit of PCT ApplicationNo. PCT/US2006/036239, filed Sep. 15, 2006, and the subject muttersthereof are hereby incorporated herein by reference thereto.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/596,338 filed on Sep. 16, 2005, and the subjectmailer thereof is hereby incorporated by reference thereon.

TECHNICAL FIELD

The present invention relates generally to radio frequencyidentification (RFID) systems, and more particularly to high volumeapplication RFID systems.

BACKGROUND ART

Currently, various products are tracked through the use of barcodeswhich are identification labels having a series of different widthvertical stripes, which are capable of being scanned using hand scannersto provide computer readable numerical codes. Generally, the scannermust be within a specific close distance and in a specific relationshipto rite barcodes to be able to read them. Barcodes are used on productsas diverse as electronic equipment, clothing, and produce.

As technology evolved, small electronic circuits have been developedthat are capable of sending and receiving radio signals, which may beused to identify different products. These circuits are called RFIDcircuits, or radio frequency identification circuits.

In one application, barcode labels (and labels with unique part numbers)are applied to circuit boards during the manufacturing process for thepurpose of tracking inventory and configuration control. Such labels aremostly “preprinted” and currently applied manually or by dedicated labelapplicator machines. Label sizes are getting smaller and barcodes arebecoming obsolete. There has been a desire to replace barcodes with RFIDcircuits and some experimental ion has been carried out in this area.

Currently, labels with embedded RFID circuits that can be “written” towith unique ID information are starting to be introduced. RFID primers(that include readers/writers) are becoming available that allow acustomer to print/read write an RFID label and apply the printed RFIDlabel manually or “off-line” to a product. This approach is acceptablein low production environments where quality/consistency requirementsare not high.

Currently also, there are manufacturing environments where highproduction and quality/consistency requirements are very high. In theseenvironments, assemblies (especially, electronic printed circuit board(PCB) assemblies) must be built in huge quantities and many differentconfigurations.

In addition to the many different configurations, high quality orientedprocesses require unique hardware and software trackingmethods/mechanisms for each and every assembly for the purpose of theconfiguration control and inventory tracking. A unique ID number isencoded in a barcode and printed on a label that needs to be affixed tothe assembly.

With the huge number of electronic and other assemblies produced, thereis a need to simplify this process, which until now has been essentiallya manual process.

One approach has been to integrate mechanized manual equipment into adistinct assembly cell (as a part of the automated production line) witha dedicated function: print and apply the printed/written labels (usinglabel applicator(s)).

Unfortunately, this approach consumes valuable production floor space.

Also, from uptime and reliability points of view, if the dedicatedassembly cell goes down, it takes down the whole assembly line. Amanufacturer cannot easily “replace” the whole assembly cell withinminutes and replacement could result in substantial and expensivedowntime.

Solutions to these problems have been long sought but prior developmentshave not taught or suggested any solutions and, thus, solutions to theseproblems have long eluded those skilled in the art.

DISCLOSURE OF THE INVENTION

The present invention provides a method of operation of a radiofrequency identification system that includes: providing a radiofrequency identification transponder; sensing the absence or presence ofthe radio frequency identification transponder at the radio frequencyidentification system; supplying the radio frequency identificationtransponder to the radio frequency identification system in the absenceof the radio frequency identification transponder at the radio frequencyidentification system; and writing transponder content to the radiofrequency identification transponder at the radio frequencyidentification system in the presence of the radio frequencyidentification transponder at the radio frequency identification system.

The present invention provides a radio frequency identification systemthat includes: a sensor for sensing the absence or presence of a radiofrequency identification transponder at the radio frequencyidentification system; a supply system connected to the sensor forsupplying the radio frequency identification transponder to the radiofrequency identification system in the absence of the radio frequencyidentification transponder at the radio frequency identification system;and a programmer connected to the sensor for writing transponder contentto the radio frequency identification transponder at the radio frequencyidentification system in the presence of the radio frequencyidentification transponder at the radio frequency identification system.

Certain embodiments of the invention have other aspects in addition toor in place of those mentioned above. The aspects will become apparentto those skilled in the art from a reading of the following detaileddescription when taken with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an assembly line in accordance with anembodiment of the present invention;

FIG. 2 is a schematic diagram of an RFID system in accordance with afirst embodiment of the present invention;

FIG. 3 is a schematic diagram of an RFID system in accordance with asecond embodiment of the present invention;

FIG. 4 is a schematic diagram of an RFID system in accordance with athird embodiment of the present invention;

FIG. 5 a schematic diagram of the internal circuit architecture of aRFID system;

FIG. 6A and 6B are plan views of RFID tags in accordance withembodiments of the present invention;

FIG. 7 is a plan view of a portion of the assembly line of FIG. 1,having a first PCB and a second PCB; and

FIG. 8 is a radio frequency identification system disclosing theoperation of the radio frequency identification system of FIG. 1 in anembodiment of the present invention.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

The following embodiments are described in sufficient detail to enablethose skilled in the art to make and use the invention, and it is to beunderstood that other embodiments would be evident based on the presentdisclosure and that process or mechanical changes may be made withoutdeparting from the scope of the present invention. The numbering of theembodiments as first, second, etc. is merely for convenience indescription.

In the following description, numerous specific details are given toprovide a thorough understanding of the invention. However, it will beapparent that the invention may be practiced without these specificdetails. In order to avoid obscuring the present invention, somewell-known circuits, system configurations, and process steps are notdisclosed in detail.

Likewise, the drawings showing embodiments of the apparatus/device aresemi-diagrammatic and not to scale and, particularly, some of thedimensions are for the clarity of presentation and are shown greatlyexaggerated in the drawing FIGs.

For purposes of the present invention, a “feeder” means anyelectromechanical (or pneumatic, or “pure” mechanical”) device thatsupplies components to a pick and place robot for assembling circuitboards. The term “system” is used to describe both the RFID apparatusand method, and the context determines which of the two is beingdescribed.

Most PCB (printed circuit board) components are delivered to thecustomer in tape (sometimes in trays, tubes, or bulk). A tape feederremoves the cover tape from the packaging carrier tape to expose eachcomponent within a tape pocket in the packaging tape. The component ispositioned so that an assembly machine robotic Pick-and-Place (PNP)mechanism can pick it up and place it on a PCB. Once a component ispicked up from a pocket, the feeder advances the tape to expose the nextcomponent. Most of the components are capacitors, resistors, ICs,micro-controllers etc.

Referring now to FIG. 1, therein is shown an isometric view of anassembly line 100 in accordance with an embodiment of the presentinvention. The assembly line 100 includes a platform 102 supporting aconveyor belt 104 for conveying printed circuit boards (PCBs) 106.

The conveyor belt 104 moves the PCBs 106, which may be unpopulated orpartially populated with components, past a robotic handling system 108mounted on a support frame 110 over the conveyor belt 104.

A feeder table 112 is attached to the platform 102 to support a numberof input feeders 114. The input feeders 114 provide electroniccomponents in line to the robotic handling system 108. The input feeders114, exemplarily, may be tape feeders. The robotic handling system 108moves a PNP head 116 along an X-Y-Z and θ coordinate system (with X andY being horizontal movements, Z being vertical, and θ being rotational)to take components from the input feeders 114 and place them on the PCBs106 to form populated or filled PCBs 118.

Adjacent to the input feeders 114 is an RFID system 120 in accordancewith a first or second embodiment of the present invention and an RFIDsystem 122 in accordance with a third embodiment of the presentinvention. The RFID system 120 also includes an assembly line RFIDreader/writer 124 (optional) connected to the assembly line 100 forreading and/or writing RFID tags (described hereinafter) during variousprocessing steps. The RFID systems 120 and 122 are generally connectedto the feeder table 112 to feed RFID tags in a first directionperpendicular to a second direction in which the conveyor belt 104 ofthe assembly line 100 moves as shown in FIG. 1.

Referring now to FIG. 2, therein is shown a schematic diagram of across-sectional view of an RFID system 200 in accordance with a firstembodiment of the present invention. The RFID system 200 may bedescribed as an automated in-line RFID supply/reader/writer/feederbecause the supply, reader, writer, and feeder are sequentially in linealong a first axis as shown in FIG. 2. As shown in FIG. 1, the assemblyline 100 moves products such as the PCBs 106 on the conveyor belt 104along a second axis perpendicular to the axis of the RFID system 200.

The RFID system 200 includes a frame 202 carrying a control system 204,shown in more detail in FIG. 5, for controlling operations and forreading and writing (programming) an RFID tag containing a transponderand an exemplary antenna as shown in FIG. 6A and described hereinafter.The frame 202 is connected to the feeder table 112 of FIG. 1.

A RFID tag supply system 206 supported by the frame 202 supplies acontinuous tape 212 of labels 208 with each label 208 having a RFID tag210. The labels 208 can be pre-printed or blank in which ease a printer(optional, not shown on FIG 2; shown as optional 314 on FIG 3) would beused to print the blank labels. The RFID tag supply system 206 may beany type of media feeder in addition to the continuous tape 212, such asbulk feeders, tubes, trays, tray stackers, etc.

A RFID reader/writer 216 is mounted on the frame 202 adjacent to thetape to read and/or write the RFID tag 210. The RFID reader/writer 216is generically referred to as a RFID programmer and is capable ofreading, writing, or reading and writing to RFID lags.

In one embodiment, the RFID tag 210 has an integral antenna and it hasbeen discovered that it is possible to wirelessly read and/or write theRFID tag 210 without contact, which eliminates a source of wear on theRFID system 200. It is even possible to read and write the RFID tag 210without removing it from the label 208. This allows a rejected RFID tagto remain on a label going into a wastebasket or cutter mechanism 218(usually mounted on the feeder table 112 or assembly machine).

The labels 208 and the RFID tag 210 are separated from the tape 212 oflabels 208 and are fed to a pick-up point 220 for pick up by the PNPhead 116 of the robotic handling system 108 of FIG. 1. The labels 208can have a heat setting adhesive on the bottom or the pick-up point 220optionally has a non-stick surface to allow adhesive to be placed on theback of the RFID tag 210 so it may be placed on the PCB 106 to be heldby a backing adhesive on the RFID tag 210. A sensor 222 is positionedadjacent the pick-up point 220 for sensing the presence of the label 208or the RFID tag 210 and its removal by the PNP head 116.

The RFID system 200 is considered an “in-line” system because the RFIDtag supply system 206, the tape 212 of labels 208, the RFIDreader/writer 216, and the pick-up point 220 are all directly in line.It also works as an inline RFID feeder system as a part of the assemblyline.

In operation, the RFID system 200 is positioned on the feeder table 112of the assembly line 100 of FIG. 1. The RFID system 200 may optionallybe connected to the computer controlling the assembly line 100. The tape212 is wound around various feed rollers (some of them not shown).

The RFID reader/writer 216 reads the RFID tag 210 to make sure that theRFID tag 210 is not defective, writing to put the correct information onthe RFID tag 210, or correcting any incorrect information on the RFIDtag 210 to assure that the information on the label 208 corresponds tothe information in the transponder of the RFID tag 210. The RFID tag 210is then fed by a feeder 219 to the pick-up point 220.

Referring now to FIG. 3, therein is shown a schematic diagram of across-sectional view of an RFID system 300 in accordance with a firstembodiment of the present invention. The RFID system 300 may bedescribed as an automated in-line RFID supply/reader/writer/labelprinter/feeder. Please note that printer could be optional here as well.

The RFID system 300 includes a frame 302 carrying a control system 304,shown in more detail in FIG. 5, for controlling operations and forreading and writing a “bare” RFID tag containing a transponder withoutan antenna as shown in FIG. 6B and described hereinafter. The frame 302is connected to the feeder table 112.

An RFID tag supply system 306 supported by the frame 302 supplies acarrier tape 308 having pockets with each pocket containing a RFID tag310.

The RFID tags 310 may come provided with labels 312 or optionally alabel feeder system (not shown) may supply the labels

A printer (optional) 314, which may be a thermal, inkjet, dot-marker, orother printer, is mounted on the frame 302 adjacent to the tape 308 toprint on the labels 312.

A RFID reader/writer 316 is mounted on the frame 302 adjacent to thetape to read and/or write the RFID tag 310.

It has been discovered that it is also possible to provide the RFID tag310 without an antenna, which makes the RFID tag 310 much less expensiveand much smaller since the antenna is usually one of the more expensiveparts of an RFID tag and often the largest. In such an embodiment, thereading and writing may be performed by direct contact by the RFIDreader/writer 316 with contacts provided on the RFID tag 310. In anothersuch embodiment, an antenna 315 on the radio frequency (RF)reader/writer 316 contacts the contacts provided on the RFID tag 310.

Where the RFID tag 310 is without an antenna, the PCB 106 of FIG. 1 willbe provided with an antenna, which will connect with the contactsprovided on the RFID tag 310. Antennas may be easily added to PCBs ormade on PCBs when making the electrical traces on the PCBs. The reflowsoldering process used to solder components on the PCB 106 will alsoconnect the RFID tag 310 to the antenna on the PCB 106.

A cover tape 313 over the pockets containing the RFID tags 310 is peeledand directed by a peel bar 318 and goes back in the opposite directionand collected by a cover tape spool 313S (optional) or a cover tapedispenser (optional, not shown). The RFID tag 310 then is fed by afeeder 319 to a pick-up point 320 for pick up by the PNP head 116 of therobotic handling system 108 of FIG. 1. The pick-up point 320 optionallyhas a non-stick surface to allow adhesive to be placed on the back ofthe RFID tag 310 so it may be placed on the PCB 106 to be held by abacking adhesive on the RFID tag 310.

A sensor 322 is positioned adjacent the pick-up point 320 for sensingthe presence of the RFID tag 310 and its removal by the PNP head 116 ofFIG. 1.

Defective RFID lags are fed to a defect bin 324 or just come out withthe empty tape 308 out of the feeder into a wastebasket.

The RFID system 300 is considered an “in-line” system because the RFIDtag supply system 306, the tape 308, the printer 314, the RFIDreader/writer 316, and the pick-up point 320 are all directly in line.

In operation, the RFID system 300 is positioned on the feeder table 112of the assembly line 100 of FIG. 1. The RFID system 300 may optionallybe connected to the computer controlling the assembly line 100. The tape308 is wound around various feed rollers.

The printer 314 prints text, part numbers, etc. on the labels 312 andthe RFID tag 310 is fed to the RFID reader/writer 316.

The RFID reader/writer 316 reads the RFID tag 310 to make sure that theRFID tag 310 is not defective, writes to put the correct information onthe RFID tag 310, or corrects any incorrect information on the RFID tag310 to assure that the information on the label 312 corresponds to theinformation in the transponder of the RFID tag 310.

Referring now to FIG. 4, therein is shown a schematic diagram of a planview of an RFID system 400 in accordance with a third embodiment of thepresent invention. The RFID system 400 may be described as an automatedvibratory bowl (bulk feeder) to feed RFID reader/writer/feeder. The RFIDsystem 400 can be especially useful for RFID tags that have aself-contained antenna and packaged in a “hard plastic” body.

The RFID system 400 includes a frame 402 carrying a control system 404,shown in more detail in FIG. 5, for controlling operations and forreading and writing a “bare” RFID tag containing a transponder withoutan antenna as shown in FIG. 6B and described hereinafter.

A RFID vibratory bowl supply system 406 supported by the frame 402provides a RFID tag 410 oriented by a feeder/orientation mechanism 408.In one embodiment, each RFID tag 410 may have an attached pre-printedlabel 413 (optional).

A RFID reader/writer 416 is mounted on the frame 402 adjacent to thefeeder orientation system 408 to read and/or write the RFID tag 410.

It has been discovered as for other embodiments that it is also possibleto provide the RFID tag 410 without an antenna, which makes the RFID tag410 much less expensive and much smaller since the antenna is usuallyone of the more expensive parts of an RFID tag and often the largest. Insuch an embodiment, the reading and writing may be performed by directcontact by the RFID reader/writer 416 with contacts provided on the RFIDlag 410. In another such embodiment, an antenna 415 on the RFIDreader/writer 416 contacts the contacts provided on the RFID tag 410.

Where the RFID tag 410 is without an antenna, the PCB 106 of FIG. 1 willbe provided with an antenna, which will connect with the contactsprovided on the RFID tag 410. Antennas may be easily made on PCBs whenmaking the electrical traces on the PCBs. The reflow soldering processused to solder components on the PCB 106 will also connect the RFID tag410 to the antenna on the PCB 106.

The RFID tag 410 is fed to a pick-up point 420 for pick up by the PNPhead 116 of the robotic handling system 108 of FIG. 1. The pick-up point420 optionally has a non-stick surface to allow adhesive to be placed onthe back of the RFID tag 410 so it may be placed on the PCB 106 to beheld by a backing adhesive on the RFID tag 410.

A sensor 422 is positioned adjacent the pick-up point 420 for sensingthe presence of the RFID tag 410 and its removal by the PNP head 116 ofFIG. 1.

Defective RFID lags are fed to a defect bin 424.

In operation, the RFID system 400 is positioned on the feeder table 112of the assembly line 100 of FIG. 1. The RFID system 400 may optionallybe connected to the computer controlling the assembly line 100.

The RFID tag 410 is fed to a RFID reader/writer 416.

The RFID reader/writer 416 reads the RFID tag 410 to make sure that theRFID tag 410 is not defective, writing to put the correct information onthe RFID tag 410, or correcting any incorrect information on the RFIDtag 410. Please note that additional devices like opticalsensors/scanners (not shown) may be used to read the information on thelabel 413 and to assure it corresponds to the information in thetransponder of the RFID tag 410, if necessary.

Referring now to FIG. 5, therein is shown a schematic diagram of theinternal circuit architecture 500 of a RFID system. The internal circuitarchitecture 500 would be in the control system 204 of FIG. 2, thecontrol system 304 of FIG. 3, and the control system 404 of FIG. 4.

The internal circuit architecture 500 includes a microprocessor orprocess controller 502, which is compatible to interface with amultitude of different types of pick-and-place and-place machines, suchas those from Siemens, Universal Instruments, Panasonic, Juki, Fuji,etc.

A process controller 502 is connected to a communication port 504 toaccept label content and formatting from a memory card, memory stick,the Internet, etc. The process controller 502 provides mechanisms forhandshaking interface among the printer, reader, writer, andpick-and-place head of the assembly line.

The process controller 502 controls a tag supply system 506, which wouldbe the RFID tag supply system 206 in FIG. 3, the RFID tag supply system306 in FIG. 4, and the vibratory bowl supply system 406 in FIG. 4.

Another processor such as a content writer controller 508 is furtherconnected to the process controller 502 to control a printer 510, suchas the printer 314 of FIG. 3, and an RFID writer/writer 512, such as theRFID reader/writer 216 of FIG. 2, the RFID reader/writer 316 of FIG. 3,or the RFID reader/writer 416 of FIG. 4. The communication protocols ofthe content writer controller 508 adhere to existing syntax used bypopular desktop labelers to minimize impact on manufacturing processes.

A label content bit memory 514 for storing label information is accessedboth by the process controller 502 and the content writer controller508.

Various sensors 516 provide information to the process controller 502 toallow it to coordinate operations of the internal circuit architecture500, such as advancing RFID tags to the pick-up point and the conditionof the tag supply system 506.

The sensors 516 allow the process controller 502 to deliver RFID tagson-demand for just-in-time operation whenever the robotic handlingsystem removes an RFID tag.

A memory stick port 518, for flash or other type of portable memories,is connected to the process controller 502 to allow programming of theprocess controller 502.

An operator control panel 520 further connects to the process controller502 to allow direct control of the process controller 502 by an operatorto make adjustments during setup.

Referring now to FIG. 6A, therein is shown an RFID tag 600 with anantenna 602. The RFID tag 600 contains a transponder 604, which is anintegrated circuit that can respond to radio frequency signals to readand write to a memory chip 606 that is part of or connected to thetransponder 604.

The RFID tag 600 also has a label 608, which allows data to be readvisually as well as electronically. In some embodiments, the RFID tag600 is thin enough to be sandwiched within the label 608.

The RFID tag 600 also comes in different embodiments, such as passive,as shown, active, and semi-active.

Passive RFID tags have no internal power supply, such as a battery, andcan have an unlimited life span. The minute electrical current inducedin the antenna by the incoming radio frequency signal provides justenough power for an integrated circuit in the RFID tag to power up andtransmit a response. Most passive RFID tags signal by reflecting acarrier signal from a reader. This means that the antenna has to bedesigned to both collect power from the incoming signal and also toreflect the signal. Passive RFID tags have practical read distancesranging from about a few inches to a few feet depending on the chosenradio frequency and antenna design/size. The RFID tag integrated circuitcan contain nonvolatile memory for storing data. Lack of an onboardpower supply means that the device can be quite small. The addition ofthe antenna creates a tag that varies from the size of a postage stampto the size of a post card.

Semi-active RFID tags have their own internal power source which is usedto power the integrated circuits that generate the outgoing signal.Active RFID tags are typically much more reliable (e.g. fewer errors)than passive RFID tags due to the ability to communicate in bothdirections with a RFID reader/programmer. Semi-active RFID tagstypically have much longer range of hundreds of feet and larger memoriesthan passive RFID tags so as to store additional information sent by thetransceiver. Semi-active RFID tags, due to their onboard power supply,also transmit at higher power levels than passive tags, and a batterylife of up to 10 years.

Active RFID tags have their own internal power source and an activeradio transmitter, which provides longer ranges of thousands of feet. Asmore sensitive RFID reader/programmers are developed, the ranges areexpected to increase.

Referring now to FIG. 6B, therein is shown an RFID tag 610 with contactsand without an antenna. The RFID tag 610 contains a transponder 614,which is an integrated circuit that can respond to radio frequencysignals to read and write to a memory chip 616, which in someembodiments is part of the same integrated circuit as the transponder.The RFID tag 610 has two contacts 618 and 620. The RFID tag 610 can alsobe passive, semi-active, and active.

Referring now to FIG. 7, therein is shown a plan view of a portion ofthe assembly line 100 of FIG. 1 having a first PCB 702 and a second PCB704. The first PCB 702 has a first type of built-in antenna 706 and thesecond PCB 704 has a second type of built-in antenna 708 with a RFID tag710 connected to it.

Referring now to FIG. 8, therein is shown a radio frequencyidentification system 800 disclosing the operation of the radiofrequency identification system 120 of FIG. 1 in an embodiment of thepresent invention. The radio frequency identification system 800includes: supplying a radio frequency identification tag includingproviding a radio frequency identification transponder and writingtransponder content to the radio frequency identification transponder ina block 802; and feeding the radio frequency identification tag for anassembly line in a block 804.

The term radio frequency identification system is used to describe boththe system 120 and the system 800 as a matter of convenience and thedetermination of whether apparatus or method is being disclosed caneasily be determined from context

While the invention has been described in conjunction with a specificbest mode, it is to be understood that many alternatives, modifications,and variations will be apparent to those skilled in the art in light ofthe aforegoing description. Accordingly, it is intended to embrace allsuch alternatives, modifications, and variations that fall within thescope of the included claims. All matters hithertofore set forth hereinor shown in the accompanying drawings are to be interpreted in anillustrative and non-limiting sense.

The invention claimed is:
 1. A method of operation of a radio frequencyidentification system comprising: providing a radio frequencyidentification transponder; sensing the absence or presence of the radiofrequency identification transponder at the radio frequencyidentification system; supplying the radio frequency identificationtransponder lo the radio frequency identification system in the absenceof the radio frequency identification transponder at the radio frequencyidentification system; and writing transponder content to the radiofrequency identification transponder at the radio frequencyidentification system in the presence of the radio frequencyidentification transponder at the radio frequency identification system.